directions:

1. Prepare beef. Heat oil in a large heavy pan on medium heat. Add roast and brown on all sides (about 2 to 3 minutes per side).

2. While beef is browning, add bay leaves, five spice powder, red wine vinegar, soy sauce (reserve 1/8 teaspoon for sauce), rice wine, garlic, and pepper to a slow cooker. Mix until well blended. Set roast on top of seasoning and turn it over to coat both sides. Pour beef broth on top of roast. Cover and cook on low for 8 hours.

3. Turn off slow cooker. Carefully remove roast from slow cooker and place onto a platter. Strain cooking juices through a sieve and discard solids. Return roast to slow cooker and cover to keep it warm while you prepare sauce.

5. Transfer cooking juices (there should be about 2 1/2 cups) into a fat separator. Pour out juices, minus fat, into a small saucepan and add brown sugar, soy sauce, and Worcestershire sauce. Over medium high heat, bring to boil. Whisk cornstarch into cold water and slowly pour mixture into saucepan, stirring constantly to avoid lumps. Mixture will thicken quickly as it boils. Turn off heat and stir in sesame oil.

5. Place baby spinach on a serving platter. Remove roast from cooker and place on cutting board. Thinly slice roast against grain and place slices on top spinach. Pour sauce over slices. Garnish with scallions.